nu ESTATES lemme. 170B; antenna was,a i iemteseeiK tte ials t,WP M QE ,This invention relates to improved means for separating dirt, bone and the like from coal and particularly coal. of the smaller type, such as nuts and'the'like after it has been passed through screens of suitable mesh whereby the coal is sorted to var ous sizes, but which still retainsalongwith' it the usualdirt and'bone, the object being to provide'a simple and improvedapparatus ltorthe purpose.

viy inyention has particular referenceto that type of known device wherein the coal containing a proportion ojt'dirt or sb'one is fed by a'ij'igger into a more orless horizontal step and pushed on to the upper ot a -se'ries oi declining smooth'plates of glass or other suitable material arranged at an etiective angle, such plateseitherbeing in the same plane or indifferent planes or-in planes having a slight angle with relation to each other but in "all cases :being provided with a gap betweenthe:lower'end ofone plate andflthe upper, endof the other. Asthe coal; with the dirt and bone is fed on to'the upper plate whose surface is wholly in one plane it leaps "orfi'slides down thefplate and the quicker travelling coal leaps overthe gaps'inthe separatorwhilst the -.dirt or bone travelling at a slower speed passes through the gaps. The foregoing is at any rate-the {objectof plates-arranged as described but; hithertothe separatingdevice has not been successful-for the reason that in some of" the known ,machines-the material is-subjected to a slidin'g action only-,orto a bouncing action only,

andin some" cases the bouncing action is -reduced to a slide and 'then the --material is caused to bounce again in contact with asecend plate. This second bounce-interferes with the efliect of the first bounce.

WVith the object of eliminating the defects of the known types of apparatus previously referred to my invention consists in subjecting the material to be separated to one collision with a declining plate, and bringing it as quickly as possible to a sliding action by bending or curving the lowerend of the plate upwardly with relation to its general surface prior to the materials being separated at the gap.

A further feature of my invention consists in employing in conjunction with the first plate a straight, bent or upwardly curved The customary intake and exhaust valves wardly, said plate beingwholly adjustable to narrow or widen the-separator gap.

ranged as describedot' a jet devicefor directing a current of QIPClQWIl the surface of "the upperplate or a succeeding plateor plates dust.

it-desired, to keepit clear or free from Myoinvention will be fully describedjwith reference to :the accompanying drawings which shows aside elevation of an apparatus constructedin accordance with myinvention. V

-JIn. the aforesaid type of apparatus and in ca rrying outmydnvention I'direct the lower end of .the-upper plate aupwardly with respect to a the general surface, of the plate at amangle asat bor-by curvingit sothat, the coaland dirt are-ibrought'more.into close contact withfit before reaching the gap 0 between the plate (Land the succeeding plate at, anduconsequently the coal has abetter chance of jumping 'the gap 0! by taking a -gr-eater parabolic c curve whilst a the dirt -or bone-by describing a lesser parabolic curve passes through the gap" To further assist in this, operation I arrange the upper end oft-the second plate dwithvanadjustable portion-f whichli s bent at an angle in an upward direction as at 9 though it may be curved upwardly and its upward edge terminateat a little distance below the upper edge of the upwardly-directly port-ion of the upper plate a. In other words the upper edge of the second plate is adjusted to lie between the parabolic paths described by the coal and dirt, such paths being shown as to the one in full line and as to the other in a broken line in the drawing. Instead of employing an adjustable plate, the second plate (2 may be bent or curved in the manner previously described at its upper end and such plate be wholly adjusted to increase or decrease the width of the gap.

, may still be mixed to some extent.

. latter and be declined in the same or in an opposite direction.

In conjunction with plates arranged as aforesaid I employ at the top of the first plate a step it of the known type either arranged horizontally or slightly declined'to which the materials to be separated are first fed in fairly regulated quantity and pushed 'over its front edge on to the upper separator plate a by a jigging action. I may also, if desired, employ one such plate or step opposite each gap to receive the partly separated material and push the latter off as before by a jigging action on to the next series of separator plates.

.It has been found by continued experiments that coal is more resilient than dirt and will bounce when dirt will not. Colliding the material to be separated by dropping it off the step it causes the coal to rebound as shown by full lines in the drawing and to travel down the plate a more quickly than the dirt which only rebounds to a lesser extent as indicated by the broken lines. Experiment has shown that if the sliding surfaces are long enough the quickly travelling coal, if the feed is quick enough, catches up the dirt sliding down in front which belongs to the feed impulse immediately prior and so the difference in speed would become neutralized and the object defeated. The

declining planes are therefore made as short as possible whilst the line of motion of the coal and dirt is made uniform. It is to this end that the lower edge of the declining plane is bent upwardly as described to finally reduce the motion of the recently fallen coal and dirt to one in which they travel at various speeds in a uniform direction. The bend or curve has also a distinct breaking or retarding action on the dirt which is in more intimate contact with the surface of the declining plate than the coal.

In conjunction with separator plates arranged as described I arrange to pass over the surface of the separator plate and particularly the upper one, a current of air which is directed by a et device 2' located beneath the step it so that the air discharged practically passes along the full length of the plate a so freeing such platefrom dust and increasing the efficiency of the apparatus.

I am aware it has previously been proposed in some forms of separatordevices to bend the plates upwardly at their lower ends but this is in apparatus in which the mate rials to be separated have a purely sliding action and that in another case declining plates have'been provided at their lower ends with an entirely separate plate of stone or slate directed upwardly and designed to retard the materials to be separated and that in conjunction with such a separate plate a straight plate has been employed to adjust the width of the separator gap. In this latter case also the materials are separated.

by a purely sliding action.

WVhat I'claim as my invention and desire to secure by Letters Patent is a In a coal separator, an upper inclined plate having its lower end portion bent upwardly, a lower inclined plate, a slidable inclined plate having its main part adjustably secured against the said lower plate and being slidable inthe plane of the lower plate said slidable plate having its upper end portion bent upwardly and being adapted to vary the width of the gap between the upper and lower inclined plates, a substantially horizontal feed plate for the coal secured above the top of the upper inclined plate, and an air jet device arranged between the feed plate and the upper plate and delivering a blast of air downwardly over the said inclined plates and the gap between them.'